1. Which one of the following types of generators does not need equilizers for satisfactory parallel operation ?

Flat-compound

Over-compound

Under-compound

Series

Answer: Under-compound

Explanation:


2. Iron losses in a D.C. machine are independent of variations in ?

speed

load

voltage

speed and voltage

Answer: load

Explanation:


3. Iron losses in a D.C. machine are independent of variations in ?

speed

load

voltage

speed and voltage

Answer: load

Explanation:


4. In case of a 4-pole D.C. generator provided with a two layer lap winding with sixteen coils, the pole pitch will be ?

4

8

16

32

Answer: 8

Explanation:


5. The insulating material used between the commutator segments is normally ?

graphite

paper

mica

insulating varnish

Answer: mica

Explanation:


6. The purpose of providing dummy coils in a generator is ?

to enhance flux density

to amplify voltage

to provide mechanical balance for the rotor

to reduce eddy currents

Answer: to provide mechanical balance for the rotor

Explanation:


7. In D.C. generators, the brushes on commutator remain in contact with conductors which ?

lie under south pole

lie under north pole

lie under interpolar region

are farthest from the poles

Answer: lie under interpolar region

Explanation:


8. For the parallel operation of two or more DC compound generators, we should ensure that ?

voltage of the incoming generator should be same as that of bus bar

polarity of incoming generator should be same as that of bus bar

all the series fields should be run in parallel by means of equilizer connection

series fields of all generators should be either on positive side or negative side of the armature

Answer: series fields of all generators should be either on positive side or negative side of the armature

Explanation:


9. ln case of a flat compounded generator ?

voltage generated is. less than the rated voltage

generated voltage is proportional to the load on the generator

voltage remains constant irrespective of the load

speed varies in proportion to the load on the generator

Answer: voltage remains constant irrespective of the load

Explanation:


10. When two D.C. generators are running in parallel an equilizer bar is used ?

to increase the series flux

to increase the generated e.m.f.

to reduce the combined effect of armature reaction of both the machines

so that the two identical machines will pass approximately equal currents to the load

Answer: so that the two identical machines will pass approximately equal currents to the load

Explanation: